1997 Cadillac Catera Radiator Warning Light Won't Reset, Stays on

Two days ago while driving I noticed that the radiator warning light had let up, I refer to the manual it was said to be low and radiator antifreeze. Antifreeze level was low so I filled it approximately a half a gallon
check for leaks no leaks. Upon restarting the engine warning light went off and came back on, even though the car is not running hot. The gauge reads about 50% or 60% below the overheat level.
Is there some type of reset for this or is the sensor assumed to be bad.
I'll appreciate any input,. Rev.

Re: 1997 Cadillac Catera Radiator Warning Light Won't Reset, Stays on

The sensor is inside the overflow tank linked to a float. The float is probably stuck. You can try loosening it up and see if it will float, but, if not, just replace the whole overflow tank. If I recall, it was only $70 or so and very easy to replace.

Re: 1997 Cadillac Catera Radiator Warning Light Won't Reset, Stays on

No offence Rev but 1/2 a gallon? These cars will bite you if you don't keep up on the maintenance. Sometimes they bite even when you do but better to be safe. Overheating can be expensive. The engine block is iron but the heads aluminum. Overheating will warp the heads leading to a cylinderhead rebuild.

Is there oil in the coolant reservoir? Check your oil for coolant. It'll appear like a creamy emultion, sort of like Mayo. If that's the case you found your leak. The oil cooler, which sits inside a coolant gallery between the cylinder heads, is probably leaking. If left alone it will ruin the engine's bearings and clog the radiator and heater core. Old worn coolant turns acidic and corrodes the oil cooler causing it to leak, '97-'98 engines were prone to this. Replacement coolers are better but not immune. Maintenance is key. Regular coolant flushes ever 2 years and oil changes every 4000 miles is my routine.

The heater Bypass Valve behind the engine is another potential leak. It leak onto the hot engine and the coolant evaporates instantly so you might not ever see any drips or puddles. Since your temp gauge reads middle (195-205 degrees) that's probably not the problem. When they go overheating isn't far behind.

One last trouble spot is the radiator itself. The end-caps are plastic and can crack. Check the area around the upper hose fitting for dried coolant stains. You can try cementing the crack but I didn't have luck trying that. Replacement radiators aren't too expensive and fairly easy to swap.